BI19: Disseminated cutaneous Nocardia in a patient on dual immunosuppressant therapy

Claire Doyle, Marta Costa Blasco and Siona Ni Raghallaigh

Beaumont Hospital, Dublin, Ireland

A 60-year-old man presented with multiple erythematous purulent plaques on his abdomen and lower legs. In addition, he had recurrent fevers, shortness of breath and exquisite tenderness of his right thigh. Medical history was significant for primary focal segmental glomerulosclerosis (FSGS). Management of his FSGS was with tacrolimus 1 g and prednisolone 60 mg once daily for the past 2 years. He had been residing in Arizona for the past 4 years with frequent work trips to West Virginia. He had a short hospital stay 2 weeks prior to this presentation, where he had been treated successfully for a dense infiltrate on his chest X-ray (CXR) with piperacillin–tazobactam. On cessation of antibiotics, he rapidly deteriorated, requiring readmission due to persistent pyrexia and lethargy. Empirical treatment with piperacillin–tazobactam, flucloxacillin and doxycycline was commenced. The patient continued to develop new cutaneous lesions and have documented fevers. Initial investigations revealed a raised white cell count and C-reactive protein of > 300 mg L^–1. Renal function showed a creatinine of 150 μmol L^–1, which was the baseline for the patient. Five sets of blood cultures had no growth, despite 5 days of monitoring. Repeat CXR revealed resolution of prior consolidation. Dedicated ultrasound and computed tomography imaging of his right thigh did not reveal any pathology that would explain the tenderness. Skin swabs were taken from two separate areas. The swab from the left knee did not grow any organisms. A swab from the left posterior calf grew coagulase-negative Staphylococcus, which was deemed clinically insignificant. Histology showed septal panniculitis with Gram-positive filamentous organisms. Tissue culture grew Nocardia species. Treatment was switched to intravenous meropenem and high-dose oral Septrin® on the advice of clinical microbiology. It is expected that he will be on antibiotic treatment for between 6 and 12 months. Nocardia species are aerobic Gram-positive filamentous organisms commonly found in soil. Most often Nocardia causes infection in those who are immunocompromised. Risk factors include long-term corticosteroid use, other immunosuppressant medication, malignancy, HIV infection, diabetes and alcoholism. The most common site of primary infection is the lung; however, dissemination via haematogenous spread can occur to skin, brain, kidneys, joints and eyes. Cutaneous manifestations of disseminated Nocardia are variable and include papules, pustules, bullae, subcutaneous nodules and ulcers. It is important to consider opportunistic pathogens in immunosuppressed patients presenting with unusual cutaneous findings. It is also important for dermatologists to consider biopsy for tissue culture in this subgroup of patients in order to ensure an accurate diagnosis. In our case, it was skin biopsy that allowed the causative pathogen to be isolated and treatment tailored accordingly.